Humpbacks in Costa Rica, and the two seasons they come

Most whale-watching coasts have a season. Costa Rica's southern Pacific has two. From roughly July to October, humpbacks arrive from the far south, from feeding grounds in the cold waters off Antarctica, to breed and give birth in the warm, sheltered water near the coast. Then, from about December to March, another population arrives from the north, from the feeding grounds off the west coast of North America. The two never quite meet, because each comes in its own hemisphere's winter, but between them they keep the bay off Uvita busy for most of the year.

Costa Rica's tourist board makes the most of this, and claims the longest humpback season in the world. Whatever the ranking, the practical point is simple: there are not many months when a boat out of Uvita has no chance of a whale.

Ballena, the whale's tail

The place to go is the Ballena Marine National Park, on the coast south of Dominical. Ballena means whale, and the park's emblem is a piece of geography that looks like one: at Punta Uvita a sandbar runs out from the beach to a rocky islet, and at low tide it is uncovered as a long spit that splits at the end into two flukes. From the hills above, it is unmistakably a whale's tail, and at low tide you can walk out along it.

The park protects the sea more than the land: a long strip of coast, its beaches and reefs, and the water beyond them, where the whales come close in to calve. Boats leave from the beaches at Uvita in the morning, when the sea is usually calmer and go out along the shore of the park.

What you see depends on the luck of the day. A mother and calf, resting at the surface, are the typical sight in this breeding ground; a male singing below the boat is sometimes heard rather than seen; and now and then a whale breaches, throwing most of its great bulk clear of the water and landing with a crash you hear a moment later. Dolphins are common, and sea turtles sometimes cross the bow.

Which season to choose

The months with the best record vary a little by source, but August and September are usually given as the peak of the southern season, and January and February as the peak of the northern one. Uvita holds a whale and dolphin festival in early September, to mark the height of the first.

There are other things to weigh. The southern whales come in the rainy season on the Pacific side, when the coast is green and quieter, the afternoons often bring downpours, and the mornings on the water are generally calm. The northern whales come in the dry season, from about December, when the weather is settled and the country is busier, especially over Christmas and New Year. If you want both the whales and the rest of the country at its driest, January and February are the months to aim for.

Tours that go there

The coast around Uvita is less visited than Manuel Antonio, further north, and most first tours of Costa Rica stop short of it. G Adventures' eleven-night Trek Hidden Costa Rica goes the whole way, walking through the forests of the south: Piedras Blancas, the Ballena Marine National Park itself, Esquipulas and Uvita, as well as Manuel Antonio National Park. It departs in November, which falls between the two seasons; whales are possible but not something to count on.

The others take the classic route, which reaches the Pacific at Manuel Antonio and Quepos, the town beside it. G Adventures' seven-night Solo-ish Costa Rica, built for travellers on their own, runs from San José to Sarapiquí in the northern lowlands, La Fortuna below the Arenal volcano, the cloud forest at Monteverde, and then Manuel Antonio and Quepos. It departs in January, February, March and December, the northern whales' months.

G Adventures' eight-night Costa Rica Quest follows a similar line, from Sarapiquí to La Fortuna, Monteverde, Quepos and Manuel Antonio, and departs in November and December.

Whichever you choose, keep a morning free for the sea, and keep your expectations honest. Whales keep their own timetables. But on this coast, in the right months, the odds are good, and the boat ride along a forested shore is worth taking for its own sake.